If you have not yet secured your WordPress.org site, you should.
Some other useful links:
Removing malware from a WordPress blog – Case study
February 12, 2012 Securi Security
Spam Link Injection Hacked and How I Hopefully Fixed It
June 30, 2009 Chris Coyier
Did Your WordPress Site Get Hacked?
June 8, 2008 Donncha O Caoimh